Hearing prosthesis processing modes based on environmental classifications

ABSTRACT

A method includes determining a first feature of a first audio signal at a first location in a signal processing path and determining, using the first feature, a first environmental classification of the first signal. Further, the method includes, based on the first environmental classification, enabling, modifying or disabling one or both of a first signal processing mode at the first location and a second signal processing mode at a second location in the signal processing path. The method also includes determining a second feature of a second audio signal at the second location and determining, using the second feature, a second environmental classification of the second signal. Further, the method includes, based on the second environmental classification, enabling, modifying or disabling one or both of the first signal processing mode at the first location and the second signal processing mode at the second location.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/143,183, entitled, “Automated Sound Processor,” filed on Apr. 29,2016, which is a continuation of U.S. application Ser. No. 14/463,867,entitled, “Automated Sound Processor with Audio Signal FeatureDetermination and Processing Mode Adjustment,” filed on Aug. 20, 2014,which is a continuation of U.S. application Ser. No. 13/650,307,entitled, “Automated Sound Processor,” filed on Oct. 12, 2012, thecontents of which are hereby incorporated in their entirety.

BACKGROUND

Various types of hearing prostheses may provide people having differenttypes of hearing loss with the ability to perceive sound. Hearing lossmay be conductive, sensorineural, or some combination of both conductiveand sensorineural hearing loss. Conductive hearing loss typicallyresults from a dysfunction in any of the mechanisms that ordinarilyconduct sound waves through the outer ear, the eardrum, or the bones ofthe middle ear. Sensorineural hearing loss typically results from adysfunction in the inner ear, including the cochlea, where soundvibrations are converted into neural signals, or any other part of theear, auditory nerve, or brain that may process the neural signals.

People with some forms of conductive hearing loss may benefit fromhearing prostheses, such as acoustic hearing aids or vibration-basedhearing aids. An acoustic hearing aid typically includes a smallmicrophone to detect sound, an amplifier to amplify certain portions ofthe detected sound, and a small speaker to transmit the amplified soundinto the person's ear. Vibration-based hearing aids typically include asmall microphone to detect sound, and a vibration mechanism to applyvibrations corresponding to the detected sound to a person's bone,thereby causing vibrations in the person's inner ear, thus bypassing theperson's auditory canal and middle ear. Vibration-based hearing aidsinclude bone anchored hearing aids, direct acoustic cochlear stimulationdevices, or other vibration-based devices.

A bone anchored hearing aid typically utilizes a surgically-implantedmechanism to transmit sound via direct vibrations of the skull.Similarly, a direct acoustic cochlear stimulation device typicallyutilizes a surgically-implanted mechanism to transmit sound viavibrations corresponding to sound waves to generate fluid motion in aperson's inner ear. Other non-surgical vibration-based hearing aids mayuse similar vibration mechanisms to transmit sound via direct vibrationof teeth or other cranial or facial bones.

Each type of hearing prosthesis has an associated sound processor. Onebasic sound processor provides an amplification to any sounds receivedby the prosthesis. However, in other example hearing prostheses, theprocessor present in the hearing prosthesis may be more advanced. Forexample, some processors are programmable and include advanced signalprocessing functions (e.g., noise reduction functions).

A traditional sound processing system includes a signal input, a varietyof processing modules, and an output. Typically, the audio signal feedsinto a linear combination of processing modules. Each processing modulehas a specific function to perform on the audio signal. Additionally,the recipient of the prosthesis may be able to enable at least oneprocessing mode for the hearing prosthesis. When the recipient selectsat least one processing mode, a subset of the processing modules areselectively enabled or disabled based on the chosen processing mode.Further, the selection of at least one processing mode may modifyparameters associated with processing modules. Thus, in the traditionalprocessing system, once at least one sound processing mode is selected,the prosthesis will continue creating an output based on the selectedsound processing mode(s).

In the traditional processing system, an Environmental Classifier may belocated at one place in the signal path, typically using a microphonesignal as input. Depending on the environment detected (e.g., eitherNoise, Speech, Speech+Noise, Music, etc.), an algorithm and parametercontrol module then decides what signal processing modes of the signalpath to enable or disable, what parameters to change, and does this forthe whole signal path. One potential disadvantage of such a scheme isthat a classification decision is made only once.

SUMMARY

As disclosed above, a traditional hearing prosthesis will receive aninput signal, process the input signal, and create an output. Generally,upon receipt of the input signal, the hearing prosthesis uses amicrophone to convert an acoustic wave into an electrical signal.Applying parameters associated with a sound processing mode, a soundprocessor of the prosthesis then transforms the electrical signal into atransformed signal, and the prosthesis produces an output based on thetransformed signal.

Advantageously, in the disclosed systems and methods, the processor maywork on an ongoing basis to optimize which sound processing modes areenabled in the sound processing pathway of a hearing prosthesis. Thesound processor in a hearing prosthesis has a variety of soundprocessing modes that may be enabled, modified or disabled in order toproduce a desired effect in the output of the hearing prosthesis.

In practice, in the example disclosed systems and methods, the soundprocessor may first classify environments from the input signal andresponsively enable a first sound processing mode based on theclassification of the input signal. In the various disclosedembodiments, the sound processor may operate in different modes toclassify the input signal and enable sound processing modes. Further,the sound processor may cause the processor to transform the inputsignal into a first transformed signal based on the enabled soundprocessing mode. The first transformed signal may be further analyzedand further sound processing modes may be enabled to create and outputsignal. Once the output signal is created, the processor may either (i)communicate the output to further circuitry, or (ii) attempt to identifyfurther classifications and responsively enable further processing modesand transformations.

In one example, the signal processor transforms the input signal intothe transformed signal by determining a first feature of the firstsignal and responsively enabling a first signal processing mode based onthe determined first feature. Additionally, the sound processor willdetermine a second feature of the intermediate signal and responsivelyenable a second signal processing mode based on the determined secondfeature. The second signal processing mode is configured to transformthe intermediate signal into a second signal. The second signal may beused as the output signal.

In some examples, the first signal processing mode and the second signalprocessing mode are chosen from a group of available processing modes.In additional embodiments, the processor is further operable todetermine a third feature of the second signal and enable a third signalprocessing mode based on the determined third feature. The third signalprocessing mode is configured to transform the second signal into thethird signal. The third signal may be used as the output signal.Embodiments also include iteratively identifying multiple signalfeatures and enabling multiple signal processing modes (not limited tothe three classifications as described previously).

In additional examples, a single classifier unit determines features andenables the signal processing modes. In other examples, or multipleclassifier units determine features and enable signal processing modes.Additionally, in some embodiments, the second feature may not bedetermined until after the first signal processing mode is enabled.

In one example, noise features are first identified and anoise-reduction mode is enabled. Next, either voice or music featuresare identified. Responsively, either a voice-enhancement mode or a musicmode is enabled. In some instances, it may not be possible to identifythe voice or music features until the noise-reduction mode has beenenabled. In some further embodiments, a signal outside the audio pathwaymay be classified and used to enable a processing mode within the audiopathway. For example, a mixing ratio may be enabled by a feature in thesignal outside the audio pathway. The mixing ratio may be used to adjustthe mixing level of at least two input signals representing audiosignals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows an example of a hearing prosthesis.

FIG. 1B shows an example of an external portion of a cochlear implantcoupled to the internal portion of the cochlear implant.

FIG. 2 is an example block diagram of a system that includes a hearingprosthesis configured according to some embodiments of the disclosedmethods.

FIG. 3 is an example block diagram of a two-stage method for use with asound processor.

FIG. 4 is an example block diagram of a sound processor with a singleselection and parameter control.

FIG. 5 is an example block diagram of a sound processor with a parallelselection and parameter control.

FIG. 6 is an example block diagram of an example hearing prosthesis withmultiple signal paths.

FIG. 7 is an example flowchart of a method for a sound processor.

DETAILED DESCRIPTION

For illustration purposes, some systems and methods are described withrespect to cochlear implants. However, many systems and methods may beequally applicable to other types of hearing prostheses. Certain aspectsof the disclosed systems and methods could be applicable to any type ofhearing prosthesis now known or later developed. Further, some of thedisclosed methods can be applied to other acoustic devices that are notnecessarily hearing prostheses. FIG. 1A shows one example of a hearingprosthesis 101 configured according to some embodiments of the disclosedsystems and methods. The hearing prosthesis 101 may be a cochlearimplant, an acoustic hearing aid, a bone anchored hearing aid or othervibration-based hearing prosthesis, a direct acoustic stimulationdevice, an auditory brain stem implant, or any other type of hearingprosthesis configured to receive and process at least one signal from anaudio transducer of the prosthesis.

The hearing prosthesis 101 includes an external portion 150 and aninternal portion 175. The external portion 150 includes a primarytransducer 102, a secondary transducer 103, and a sound processor 104,all of which are connected directly or indirectly via circuitry 107 a.The internal portion 175 includes an output signal interface 105, outputelectronics 108, and a secondary processor 106, all of which connectdirectly or indirectly via circuitry 107 b. In other embodiments, thehearing prosthesis 101 may have additional or fewer components than theprosthesis shown in FIG. 1A. For example, secondary transducer 103 isomitted in some embodiments. Additionally, the components may bearranged differently than shown in FIG. 1A. For example, depending onthe type and design of the hearing prosthesis, the illustratedcomponents may be enclosed within a single operational unit ordistributed across multiple operational units (e.g., an external unitand an internal unit). Similarly, in some embodiments, the hearingprosthesis 101 additionally includes one or more processors (not shown)configured to determine various settings for either sound processor 104or secondary processor 106.

In embodiments where the hearing prosthesis 101 is a cochlear implant,the hearing prosthesis comprises an external portion 150 worn outsidethe body and an internal portion 175 located or implanted within thebody. The external portion 150 is coupled to the internal portion 175via an inductive coupling pathway 125. The primary transducer 102receives acoustic signals 110, and the sound processor 104 analyzes andencodes the acoustic signals 110 into a group of electrical stimulationsignals 109 for application to an implant recipient's cochlea via anoutput signal interface 105 communicatively connected to outputelectronics 108.

In some embodiments, some or all of the sound processor 104 circuitry islocated in another separate external portion (not shown). For example,the sound processor 104 may be located in a standard computer, a laptopcomputer, a tablet computing device, a mobile device such as a cellularphone, or a remote control or other custom computing device. The primarytransducer 102 may wirelessly communicate signals to the sound processor104. Further, the external portion 150 may also include a secondarytransducer 103. The secondary transducer 103 may be the same type oftransducer as the primary transducer 102. However, in some embodiments,the secondary transducer 103 is a different type of transducer than theprimary transducer 102. For example, both transducers are microphones;however, each may have a different beam pattern.

For a cochlear implant, the output electronics 108 are an array ofelectrodes. Individual sets of electrodes in the array of electrodes aregrouped into stimulation channels. Each stimulation channel has at leastone working electrode (current source) and at least one referenceelectrode (current sink). During the operation of the prosthesis, thecochlear implant applies electrical stimulation signals to a recipient'scochlea via the stimulation channels. It is these stimulation signalsthat cause the recipient to experience sound sensations corresponding tothe sound waves received by the primary transducer 102 and encoded bythe processor 104.

FIG. 1B shows an example of an external portion 150 of a cochlearimplant communicatively coupled to the internal portion 175 of thecochlear implant. The external portion 150 is directly attached to thebody of a recipient and the internal portion 175 is implanted in therecipient. The external portion 150 typically comprises a housing 116,that includes a primary transducer 102 for detecting sound, a soundprocessing unit (104 of FIG. 1A), an external coil 108 including a radiofrequency modulator (not shown) and a coil driver (not shown), and apower source (not shown). External coil 108 is connected to atransmitter unit (not shown) and the housing 116 by a wire 120. Thehousing 116 typically is shaped so that it can be worn and held behindthe ear. In some embodiments, the external portion 150 may also includea secondary transducer 103. The sound processing unit in the housing 116processes the output of the transducer 102 and generates coded signalsthat are provided to the external coil 108 via the modulator and thecoil driver.

The internal portion 175 comprises a housing 164. Located within housing164 are a receiver unit (not shown), a stimulator unit (not shown), anexternal portion sensor (not shown), a power source (not shown), and asecondary processor (106 of FIG. 1A). Attached to the housing 164 are aninternal coil 158 and an electrode assembly 160 that can be inserted inthe cochlea. Magnets (not shown) may be secured to the internal(receiving) coil 158 and the external (transmitting) coil 108 so thatthe external coil 108 can be positioned and secured via the magnetsoutside the recipient's head aligned with the implanted internal coil158 inside the recipient's head. The internal coil 158 receives powerand data from the external coil 108.

The internal portion 175 has a power source, such as a battery orcapacitor, to provide energy to the electronic components housed withinthe internal portion 175. In some embodiments, the external portion 150is able to inductively charge the power source within the internalportion 175. In an example embodiment, a power source that is part ofthe external portion 150 is the primary power source for the hearingprosthesis. In this example, the power source within the internalportion 175 is only used as a backup source of power. The battery in theinternal portion 175 is used as a backup power source when either theexternal portion 150 runs out of power or when the external portion 150is decoupled from the internal portion 175. The electrode assembly 160includes a cable that extends from the implanted housing 164 to thecochlea and terminates in the array of electrodes. Transmitted signalsreceived from the internal coil 158 are processed by the receiver unitin the housing 164 and are provided to the stimulator unit in thehousing 164.

The external coil 108 is typically held in place and aligned with theimplanted internal coil via the noted magnets. In one embodiment, theexternal coil 108 is configured to transmit electrical signals to theinternal coil via a radio frequency (RF) link. In some embodiments, theexternal coil 108 is also configured to transmit electrical signals tothe internal coil via a magnetic (or inductive) coupling.

FIG. 2 shows one example system 200 that includes a hearing prosthesis220 configured according to some embodiments of the disclosed methods,systems, and hearing prostheses. In an exemplary embodiment, the hearingprosthesis 220 is a cochlear implant. In other embodiments, the hearingprosthesis 220 is a bone-anchored device, a direct acoustic stimulationdevice, an auditory-brain-stem implant, an acoustic hearing aid, or anyother type of hearing prosthesis configured to assist a prosthesisrecipient in perceiving sound.

The hearing prosthesis 220 illustrated in FIG. 2 includes a datainterface 236, at least one audio transducer 232, one or more processors230, an output signal interface 238, data storage 234, at least oneanalog-to-digital converter 242, and a power supply 240, all of whichare illustrated as being connected directly or indirectly via a systembus or other circuitry 270. Further, the one or more processors 230 maybe located within the hearing prosthesis 220 and/or located in anexternal computing device.

The power supply 240 supplies power to various components of the hearingprosthesis 220 and can be any suitable power supply, such as anon-rechargeable or rechargeable battery. In one example, the powersupply 240 is a battery that can be recharged wirelessly, such asthrough inductive charging. Such a wirelessly rechargeable battery wouldfacilitate complete subcutaneous implantation of the hearing prosthesis220 to provide a fully implantable prosthesis. A fully implanted hearingprosthesis has the added benefit of enabling the recipient to engage inactivities that expose the recipient to water or high atmosphericmoisture, such as swimming, showering, etc., without the need to remove,disable or protect, such as with a water/moisture proof covering orshield, the hearing prosthesis.

The data storage 234 generally includes any suitable volatile and/ornon-volatile storage components. Further, the data storage 234 includescomputer-readable program instructions and perhaps additional data. Insome embodiments, the data storage 234 stores an amplitude response, aphase response, and recipient-specific parameters associated with thehearing prosthesis 220. Additionally, the data storage 234 stores a setof signal processing modes and associated parameters for each respectivesignal processing mode. In other embodiments, the data storage 234 alsoincludes instructions used to perform at least part of the disclosedmethods and algorithms, such as method 700 described with respect toFIG. 7 . Further, the data storage 234 may be configured withinstructions that cause the processor 230 to execute functions relatingto any of the modules disclosed herein.

In other embodiments, the analog-to-digital converter 242 receives theinput signal from the audio transducer 232 via the system bus or otherknown circuitry 270. In such embodiments, the processors 230 include adigital signal processor or similar processor suitable for processingdigital audio signals.

In the illustrated example, the audio transducer 232 is anomnidirectional microphone. In alternative embodiments, the audiotransducer 232 is one or more directional microphone(s), omnidirectionalmicrophone(s), electro-mechanical transducer(s), and/or any other audiotransducer(s) or combination of audio transducers suitable for receivingaudio signals for the hearing prosthesis utilized. The audio transducer232 receives, for example, an audio signal 215 from an audio source 210and supplies input signal to the processor 230.

In the present example, the processor 230 is configured to operate in aplurality of sound processing modes. A subset of example soundprocessing modes includes noise reduction, gain control, loudnessmapping, wind-noise reduction mode, beam-forming mode, voice enhancementmode, feedback reduction mode, compression timing mode, and music mode.In some circumstances, the audio transducer 232 also receives wind noiseand/or other noise, as a component of the input signal. To remove thewind noise, one method for example is to subtract a signal representingwind noise from the input signal. However, other methods may be used toremove the wind noise from the input signal.

The processor 230 receives the input signal and analyzes the signal todetermine at least one sound processing mode to apply to the signal. Theprocessor 230 uses features of the input signal to determine anappropriate sound processing mode. Once a sound processing mode isdetermined, the sound processing mode is applied to the input signalwith the processor 230 to create a first transformed signal. Theprocessor 230 further analyzes the first transformed signal to determineany further processing modes to apply to the first transformed signal.The processor 230 is able to identify a desirable second soundprocessing mode that would have gone unnoticed if the first signalprocessing mode had not been applied.

For example, the processor 230 may identify wind noise as a component ofthe input signal and responsively enable a wind-noise reduction mode.Further, once a first sound processing mode is enabled, the processor230 transforms the input signal into a first transformed signal andanalyzes the first transformed signal to determine additional soundprocessing modes to enable. For example, after the wind-noise reductionmode is enabled, the processor 230 may enable a voice enhancement mode.The processor 230 creates an output based on the application of bothsound processing modes. Further, the processor 230 may transform theinput signal into the output using methods similar to method 700described with respect to FIG. 7 .

In some situations, the sound processor is located in a remote computingdevice and processes a portion of the signal. In such cases, data istransmitted via an input/output device 260. The input/output device 260is, for example, a remote computer terminal suitable for issuinginstructions to the processor. The input/output device 260 transmits therequest to the data interface 236 via a communication connection 265.The communication connection 265 may be any suitable wired connection,such as an Ethernet cable, a Universal Serial Bus connection, a twistedpair wire, a coaxial cable, a fiber-optic link, or a similar physicalconnection, or any suitable wireless connection, such as Bluetooth,Wi-Fi, WiMAX, and the like.

The data interface 236 transmits data to the processor 230. The datatransmitted may include both received audio signals and an indication ofa signal processing mode. Upon receiving the data, the processor 230performs a plurality of sound processing modes. In some embodiments, theprocessor 230 continues to process the data in this manner until therecipient transmits a request via the input/output device 260 to returnto a normal (or default) signal processing mode.

Various modifications can be made to the hearing prosthesis 220illustrated in FIG. 2 . For example, the hearing prosthesis 220 mayinclude additional or fewer components arranged in any suitable manner.In some examples, the hearing prosthesis 220 includes other componentsto process external audio signals, such as components that measurevibration in the skull caused by audio signals and/or components thatmeasure electrical output of portions of a person's hearing system inresponse to audio signals. Further, depending on the type and design ofthe hearing prosthesis 220, the illustrated components may be enclosedwithin a single operational unit or distributed across multipleoperational units (e.g., two or more internal units or an external unitand an internal unit).

FIG. 3 is a block diagram of a two-stage method 300 for use with a soundprocessor (such as processor 104 of FIG. 1A or processor 230 of FIG. 2). As part of method 300, the sound processor 104 receives an inputaudio signal 302 and transforms it into an output 318. The method 300contains two stages, the first stage includes a first classifier 304, afirst selection and parameter control 306, and pre-processing 308, whilethe second stage includes a second classifier 312, a second selectionand parameter control 314, and post-processing 316. In between the twostages, the method 300 has a processing element 310. The arrangement ofthe blocks in FIG. 3 is one example layout. In different embodiments,some blocks are combined, added, or omitted. For example, method 300 maybe expanded to include more than two stages.

The method 300 distributes some sensing and control functions throughoutthe signal path. Thus, the input audio signal 302 is analyzed more thanonce to determine what signal processing functions should be enabled.For example, if noise were detected at the microphone inputs, abeam-forming mode could be enabled. Selecting a beam could result inclearer signal after the first pre-processing stage 308. This clearersignal can then be further analyzed, to determine which type of signalis now present. For example, the analysis of the clearer signal mayindicate that the signal represents speech, or perhaps music. Dependingon this result, the sound processor 104 may enable a speech enhancementalgorithm, or a music enhancement algorithm, as appropriate. Thus, byanalyzing the input audio signal 302 more than once, an increasedknowledge of the signal can be obtained. Based on this increasedknowledge, additional signal processing modes may be enabled.

Method 300 may use environmental sound classification to determine whichprocessing mode to enable. In one embodiment, environment classificationmay include four steps. A first step of environmental classification mayinclude feature extraction. In the feature extraction step, a soundprocessor may analyze an audio signal to determine features of the audiosignal. For example, to determine features of the audio signal, thesound processor may measure the level of the audio signal, themodulation depth of the audio signal, the rhythmicity of the audiosignal, the spectral spread of the audio signal, the frequencycomponents of the audio signal, and other signal features.

Next, based on the measured features of the audio signal, the soundprocessor will perform scene classification. In the scene classificationstep, the sound processor will determine a sound environment (or“scene”) probability based on the features of the audio signal. Someexample environments are speech, noise, speech and noise, and music.Once the environment probabilities have been determined, the soundprocessor may perform some post processing and/or smoothing. Postprocessing and/or smoothing of the environment probabilities may berequired, in order to provide a desired transition or othercharacteristic between the environment probabilities, before furtherprocessing is allowed. In one example, the system may transition betweendetected environments no quicker than every 30 seconds. In anotherexample, the system may enhance or otherwise modify the probability ofcertain environments with respect to other environments.

Finally, the sound processor may select a sound processing mode based onpost processing and/or smoothing of the scene classification. Forexample, if the resulting detected sound scene is classified as music, amusic-specific sound processing mode may be enabled. The selected soundprocessing mode can be applied to one or more audio signals.

More specifically, the first classifier 304 analyzes the input audiosignal 302. In some embodiments, the first classifier 304 is a speciallydesigned processor (such as processor 104 of FIG. 1A or processor 230 ofFIG. 2 ). Further, at the first classifier 304, the processor 104detects features from the input audio signal 302 of the system (forexample amplitude modulation, spectral spread). Upon detecting features,the sound processor responsively uses these features to classify thesound environment (for example into speech, noise, music). The soundprocessor makes a classification of the type of signal present based onfeatures associated with the audio signal. In some embodiments, othersignal processing techniques other than environmental classification maybe used as the first classifier 304 (or the second classifier 312). Forexample, wind noise may be identified based on a frequency analysis ofthe input audio signal 302. Where environmental classification ismentioned in this disclosure, other signal processing techniques may beused as well.

At block 306, the processor 104 in the hearing prosthesis 101 performsselection and parameter control based on the classification from thefirst classifier 304. The sound processor 104 selects one or moreprocessing modes. Further, the sound processor 104 also controlsparameters associated with the processing mode. For example, if at block304, the sound processor detects noise, it may also decide that thenoise-reduction mode should be enabled, and/or the gain of the hearingprosthesis 101 should be reduced appropriately. Further, the processingmode selected at block 306 may be applied to the input audio signal 302at block 308.

The data determined at step 306 may take many forms depending on thespecific embodiment. For example, the data may indicate a processingmode in which the processor should operate or the data may indicateparameters associated with a specific processing function. In anotherexample embodiment, the data is a set of parameters by which totransform the input audio signal 302. In yet another embodiment, thedata is a mathematical formula that can be used by the processor totransform the input audio signal 302.

At block 308, the processor 104 receives both (i) input audio signal 302and (ii) data determined at block 306, and the processor responsivelyperforms a pre-processing function. The processor 104 transforms theinput audio signal 302 into a transformed signal based on the datadetermined at block 306. For example, at block 308, the processor 104 inthe hearing prosthesis 101 may have a set of one or more processingmodes that it uses to transform the input audio signal 302. Based on theclassification of the input audio signal 302 by the first classifier 304module, the selection and parameter control module 306 indicates atleast one sound processing mode for the processor 104 to use at block308.

After the processor 104 transforms the signal at block 308, theprocessor may further filter the signal at block 310. The processingelement 310 causes the processor 104 to apply further filtering andsignal processing to the transformed signal. In some embodiments, thehearing prosthesis 101 is programmed with parameters specific to a givenprosthesis recipient. For example, recipient-specific parameters includeacoustic gain tables, frequency response curves, and other audioparameters. In some embodiments, the processing element 310 causes theprocessor 104 to adjust audio parameters based on a hearing impairmentassociated with the prosthesis recipient.

Following the processing element 310 function, the audio signal isanalyzed by a second classifier 312. Similar to the first classifier304, the second classifier 312 is performed by an audio processor (suchas processor 104 of FIG. 1A or processor 230 of FIG. 2 ). As with thefirst classifier 304, at the second classifier 312 the sound processor104 detects features from an audio signal of the system (for exampleamplitude modulation, spectral spread). However, the second classifier312 detects features from the audio signal output from processingelement 310 rather than from the input audio signal 302. Upon detectingfeatures, the sound processor responsively uses these features toclassify the sound environment (for example into speech, noise, music).

In some embodiments, the second classifier 312 detects a different setof features than the first classifier 304. The signal processing appliedat blocks 308 and 310 transforms the signal so that previouslyundetectable features can be detected. For example, the secondclassifier 312 may detect the signal from the processing element 310contains music. The first classifier 304 may have not been able todetect the music due to noise in the system and step 308 may haveincluded a noise-reduction function. Thus, by classifying the signal atmore than a single point in the audio pathway, more some previouslyundetectable features may be detected.

At block 314, the processor in the hearing prosthesis performs selectionand parameter control based on the classification from the secondclassifier 312. Similar to block 306 as discussed previously, at block314 the sound processor 104 selects one or more processing modes basedon the determination made by the second classifier 312. Further, thesound processor 104 also controls parameters associated with this secondselected processing mode. For example, if at block 312, the soundprocessor detects music, it may also decide that the music mode shouldbe enabled, and/or other parameters of the system should be adjustedappropriately. Further, the processing mode selected at block 314 may beapplied at block 316 to the signal output by the processing element 310.The data determined at block 314 may take many forms depending on thespecific embodiment. For example, the data may indicate a processingmode in which the processor should operate or the data may indicateparameters associated with a specific processing function. In theexample, at block 314, the processor 104 in the hearing prosthesis has aset of one or more processing modes that it may use to transform thesignal output by the processing element 310.

At block 316, the processor 104 receives both (i) the signal output bythe processing element 310 and (ii) data determined at block 314 and theprocessor responsively performs a post-processing function. Theprocessor 104 transforms the signal into an output 318 based on the datadetermined at block 314. Based the classification of the signal by thesecond classifier 312 module, the selection and parameter control module314 indicates at least one sound processing mode for the processor touse at block 316.

After post-processing at block 316 is completed, the processor 104creates an output 318. The output can take many different forms,possibly dependent on the specific type of hearing prosthesis 101implementing method 300. In one aspect, where the hearing prosthesis 101is an acoustic hearing aid, the audio output will be an acoustic signal.Thus, the output 318 is an electronic signal provided to a speaker tocreate the audio output. In another embodiment, where the hearingprosthesis 101 is a cochlear implant, the output 318 of the hearingprosthesis 101 is a current supplied by an electrode (such as electrodeassembly 160 of FIG. 1B). Thus, the output from 318 may be an electricalsignal provided to the output electronics that control the electrodeassembly. Additionally, the output may be supplied to further electricalcomponents.

In some further embodiments, each stage in method 300 may sharecommunication with the other stages. An example of this communication isshown with the dotted lines of FIG. 3 . For example, the processor 104in the hearing prosthesis 101 performs selection and parameter controlbased on the classification from the first classifier 304 as well as theclassification provided by the second classifier 312. Thus, in someembodiments, both classifiers may determine the parameter control andselection. The shown communication is only one example of thecommunication between stages. In other embodiments, each element of thefirst stage may communicate with its respective element pair in thesecond (and later) stage. In still further embodiments, at least oneelement of one stage may communicate with at least one or more elementsof any other stages in method 300.

FIG. 4 is an example block diagram of a sound processor 400 with asingle selection and parameter control. The sound processor 400 receivesan input 402 and transforms it into an output 422. The sound processor400 contains a plurality of modules 404 a-404 c. Each module 404 a-404 cis configured with an analysis function 406 a-406 c and a selection andparameter control 408 a-408 c. In some embodiments, selection andparameter control 408 a-408 c may be a switch to enable, modify ordisable a given module. Further, each module 404 a-404 c is configuredwith its own specific sound processing function 420 a-420 c. Forexample, one module may a wind-noise reduction module, another modulemay be an automatic sensitivity control (ASC) module, and so on.

Additionally, the sound processor 400 contains a select function 416. Inone embodiment, the select function 416 is configured with a signalinformation unit 414 and with an output unit 418. The various modules ofFIG. 4 may perform functions similar to those of the first and secondclassifiers 304 and 312, selection and parameter control 306 (and 314)and either pre-processing 308 or post-processing 316 (of FIG. 3 ).

The analysis function 406 a-406 c of each module 404 a-404 c provides asignal 412 a-412 c to the signal information unit 414 of the selectionfunction 416. Additionally, the output unit 418 of the select function416 provides a signal 410 a-410 c to each of the selection and parametercontrols 408 a-408 c of each of the modules 404 a-404 c. In oneembodiment, the signal 410 a-410 c to each of the selection andparameter controls 408 a-408 c is an indication for the switch to togglestates to either enabled or disabled. In another embodiment, the signal410 a-410 c to each of the selection and parameter controls 408 a-408 cis both a toggle as well as a parameter control for the respectivemodule.

In different embodiments, some blocks are be combined, added, oromitted. For example, sound processor 400 is shown with three modules404 a-404 c, however, in some embodiments more or fewer modules may beused. Additionally, not every module may contain both an analysisfunction as well as a switch. The block diagram shown in FIG. 4 is oneexample layout. Additionally, in some embodiments, sound processor 400may operate in a single calculation mode. For example, sound processor400 may enable or disable all modules present in sound processor 400when a signal is first analyzed. However, in another embodiment, soundprocessor 400 may continuously (or iteratively) enable or disablemodules as the input signal changes.

When one of the modules 404 a-404 c receives an input signal, theanalysis function 406 a-406 c within the module determines features ofthe input signal based on the function of the specific module. In oneexample, the analysis function 406 a-406 c of each module extractsfeatures from the audio inputs of the hearing prosthesis (for exampleamplitude modulation, spectral spread), and the select function 416 usesthese features to “classify” the sound environment (for example, speech,noise, music) similar to the environmental sound classificationdescribed with respect to FIG. 3 . Additionally, in some embodiments,other signal processing techniques—not necessarily environmental soundclassification—may be used to identify features of the audio input.

For example, a wind-noise reduction module extracts features of theinput signal that indicate the presence of wind noise. The analysisfunction 406 a-406 c then responsively determines if the extractedfeatures indicate the presence of a windy environment. Further, theanalysis function 406 a-406 c provides information 412 a-412 c from themodules 404 a-404 c to the signal information unit 414 based on thedetermined environment. In some alternative embodiments, the analysisfunction 406 a-406 c provides information 412 a-412 c from the modules404 a-404 c to the signal information unit 414 based on the determinedfeatures of the input signal.

Additionally, each module 404 a-404 c has an associated signalprocessing function 420 a-420 c. Each signal processing function 420a-420 c transforms a first signal into a second signal based onmodifying at least one feature of the first signal to create the secondsignal. In turn, the features are modified based on signal processingparameters associated with the signal processing function for therespective module. For example, the features of the audio signal may bemodified by a signal processing function may include acoustic gaintables, frequency response curves, and other functions designed tomodify audio features. Further, each module 404 a-404 c is enabled,modified or disabled based on the selection and parameter controls 408a-408 c associated with the respective module. When a module 404 a-404 cis disabled, the output signal from the module is a signal that issubstantially similar to the input to the module. However, the analysisfunction may still operate when a given module is disabled.

When the selection function 416 receives signal information 412 a-412 cfrom each module 404 a-404 c with the signal information unit, theselection function 416 determines which modules should be enabled. Theselection function 416 analyzes the information 412 a-412 c from themodules 404 a-404 c to determine which module(s) should be enabled. Theselection function 416 makes the determination of what modules to enablebased on signal information 412 a-412 c as well as the functionassociated with each module. Further, the selection function 416 maycontinuously determine which module(s) should be enabled. In anotherembodiment, the hearing prosthesis determine which module(s) should beenabled at specific time intervals. In a further embodiment, the hearingprosthesis determine which module(s) should be enabled when the ambientaudio conditions change. For example, the hearing prosthesis may detecta change in the ambient audio conditions, such as the change in ambientaudio conditions when a prosthesis recipient walks into a noisy room,and responsively determine which module(s) should be enabled to help tooptimize sound quality.

After determining the recommended status for each module 404 a-404 c(i.e., whether each is enabled or disable), the selection function 416the output unit 418 of the select function 416 will provide a signal 410a-410 c to each of the selection and parameter controls 408 a-408 c ofeach of the modules 404 a-404 c. The signal provided to each selectionand parameter control 408 a-408 c indicates whether each respectivemodule 404 a-404 c should be enabled or disabled.

When a module it toggled from one state to another (e.g., switched fromdisabled to enabled), the signal processing functions applied to thesignal by the respective module will change. Because the signalprocessing function will change responsive to a switching of at leastone of the modules, the respective output of each analysis function 406a-406 c responsively changes based on the change in signal processingapplied to the input signal 402. Thus, a switch in one of the modulesmay cause a propagation through the system that results in other modulesbeing toggled too.

In one example, Module A 404 a may be a noise reduction module, Module B404 b may be an ASC module, and Module C 404 c may be a voice enhancingmodule. In this example, all modules are initially disabled. However, inother embodiments, the modules 404 a-404 c may initially be eitherenabled or disabled. When an input signal 402 is received, the signalfirst goes to Module A 404 a. At Module A 404 a, the associated analysisfunction 406 a determines features of the input signal 402 related tonoise. Here, the analysis function 406 a determines the featuresindicate a high level of noise as a part of input signal 402 and returnsinformation 412 a indicating the high noise level to the signalinformation unit 414. Because Module A 404 a is initially disabled, theModule A 404 a outputs Module B 404 b a signal substantially similar tothe input signal 402.

At Module B 404 b, the associated analysis function 406 b determinesfeatures of the input signal 402 related to the ASC function. In thisexample, the analysis function 406 b may not be able to determine thenoise floor of the signal due to the high noise level, thus the analysisfunction 406 b returns information 412 b indicating the analysisfunction 406 b determined no relevant features to the signal informationunit 414. Because Module B 404 b is disabled, Module B 404 b outputsModule C 404 c a signal substantially similar to the input signal 402.

At Module C 404 c, the associated analysis function 406 c determinesfeatures of the input signal 402 related to the voice enhancementfunction. In this example, the analysis function 406 c may not be ableto determine any relevant features of the signal due to the high noiselevel, thus analysis function 406 c returns information 412 c indicatingthe analysis function 406 c determined no relevant features to thesignal information unit 414. Because Module C 404 c is disabled, ModuleC 404 c outputs a signal substantially similar to the input signal 402.

Based on the information 412 a-412 c received with the signalinformation unit 414, the select function 416 determines that thehearing prosthesis is operating in a noisy environment. Thus, the selectfunction 416 indicates to the output unit 418 to send a signal 410 a tothe selection and parameter control 408 a in Module A 404 a. The signal410 a causes the module to switch to an enabled mode. When Module A 404a is enabled, it will perform a noise reduction algorithm on the inputsignal 402. Thus, after Module A 404 a is enabled, it produces an outputthat is based on input signal 402, but with the application of a noisereduction function. This noise-reduced signal is the input to Module B404 b. The analysis function 406 b in Module B 404 b may now be able todetermine features associated with the ASC. Once the analysis function406 b determines these features, the analysis function 406 b will returninformation 412 b indicating the determined features signal informationunit 414. However, because Module B 404 b is still disabled, the outputof Module B 404 b is the same as its input. In this example, in Module C404 c may still not be able to detect any features related to the voiceenhancement function. Thus, the information 412 c returned to signalinformation unit 414 may remain unchanged. Further, the output of ModuleC 404 c will be substantially similar to is input (i.e. the output ofModule B 404 b).

When the signal information unit 414 receives information 412 bindicating features associated with the ASC, the select function 416 maydetermine that it should enable Module B 404 b. Thus, the selectfunction 416 indicates to the output unit 418 to send a signal 410 b tothe selection and parameter control 408 b in Module B 404 b. The signal410 b that causes the module to switch to an enabled mode. When Module B404 b is enabled, Module B 404 b will perform an ASC algorithm on theinput signal it received from Module A 404 a. Thus, in this example,after Module B 404 b is enabled, Module B 404 b produces an output thatis based on input signal 402, but with the application of noisereduction (applied by Module A 404 a) as well as the application of theASC algorithm. This noise-reduced and ASC altered signal is the input toModule C 404 c. However, because Module C 404 c is still disabled, theoutput of Module C 404 c is the same as its input. Nevertheless, becausethe analysis function 406 c can now analyze a signal that has been bothnoise-reduced and ASC altered, analysis function 406 c may be able todetect features related to the voice enhancement function. The featuresanalysis function 406 c detects will be reported by information 412 creturned to signal information unit 414.

Similar to the previous discussion, when the signal information unit 414receives information 412 c indicating features associated with the voiceenhancement function, the select function 416 may determine that itshould enable Module C 404 c. Thus, the select function 416 may indicatethe output unit 418 to send a signal 410 c to the selection andparameter control 408 c in Module C 404 c that causes the module toswitch to an enabled mode. When Module C 404 c is enabled, it willperform a voice enhancement algorithm on the input signal it receivedfrom Module B 404 b. Thus, in this example, after Module C 404 c isenabled, it produces an output that is based on input signal 402, butwith the application of (i) a noise reduction algorithm (applied byModule A 404 a), as well as the application of (ii) the ASC algorithm(applied by Module B 404 b), an also (iii) the application of the voiceenhancement algorithm. This noise-reduced, ASC-altered, voice-enhancedsignal is the output 422 for this specific example.

The above example is one way in which the sound processor 400 operates.In other embodiments, the select function 416 disables some modulesduring operation. In yet further embodiments, the select functioncommunicates revised parameters to the various modules.

FIG. 5 is an example block diagram of a sound processor 500 withparallel control. The sound processor 500 receives an input 502 andtransforms it into an output 520. The sound processor 500 contains aplurality of modules 504 a-504 c. Each module 504 a-504 c is configuredwith an analysis function 506 a-506 c, a selection function 516 a-516 c,and a switch 508 a-508 c. Further, each module 504 a-504 c is configuredwith its own specific sound processing function (not shown). Forexample, one module may be a wind-noise reduction module, another modulemay be an automatic sensitivity control (ASC) module, etc. Additionally,the various modules of FIG. 5 may perform functions similar to those ofthe first and second classifiers 304 and 312, selection and parametercontrol 306 (and 314) and either pre-processing 308 or post-processing316 (of FIG. 3 ).

Overall, sound processor 500 behaves in a similar fashion to soundprocessor 400 with the exception that sound processor 500 has selectionfunctions incorporated into the modules 504 a-504 c rather than onecentralized selection function module 416 (of FIG. 4 ). However, eachselection function 516 a-516 c may function similarly to the sectionfunction 416 of FIG. 4 . Each selection function 516 a-516 c determinesa state, either enabled or disabled, for each module 504 a-504 c in thesignal path. As shown in FIG. 5 , only modules A and B are currentlyoutputting control signals. FIG. 5 will be used to reference one mode ofoperation of the methods and apparatuses described herein. The controlsignals may be connect from and to the modules on other configurationsnot explicitly shown in the figures. Further, more or fewer modules maybe used as well.

The analysis function 506 a-506 c of each respective module 504 a-504 cprovides a respective signal 512 a-512 b to the analysis function 506a-506 c of each other module 504 a-504 c. Further, each respectivemodule 504 a-504 c has a selection function 516 a-516 c configured toprovide a respective signal 510 a-510 b to the switch 508 a-508 c ofeach other module 504 a-504 c. Additionally, each selection function 516a-516 c provides a signal (not shown) with the respective switch 508a-508 c of the same module. In one embodiment, the signal 510 a-510 b toeach of the switches 508 a-508 c is an indication for the switch totoggle states to either enabled or disabled. In another embodiment, thesignal 510 a-510 b to each of the switches 508 a-508 c is both a toggleas well as a parameter control for the respective module. In differentembodiments, some blocks are combined, added, or omitted. For example,sound processor 500 is shown with three modules 504 a-504 c; however, insome embodiments more or fewer modules may be used. Additionally, notevery module may contain both an analysis function as well as a switch.The block diagram shown in FIG. 5 is one example layout.

Sound processor 500 shows a single analysis function 506 a-506 c persignal processing module 504 a-504 c. The analysis functions 506 a-506 ccan include any of the steps as described with respect to FIG. 3 or FIG.4 , such as feature extraction, classification and classificationpost-processing. Each module 504 a-504 c of the signal path has theability to determine based on any of the module's inputs, outputs, oranalyses, or the inputs, outputs and analyses of any other module on thesignal path, whether it should be enabled, disabled or have modifiedparameters for the given sound signal it is processing. It can alsodetermine whether other modules 504 a-504 c of the signal path should beenabled or disabled or have modified parameters. In some embodiments,when the sound environment changes, each function available in thesignal path is automatically evaluating whether its current state shouldchange, based on the information available to it.

Sound processor 500 shows a distributed algorithm for the soundprocessor. Each module, A through to C, can be considered to containsome kind of analysis function or functions, depending on the overallpurpose of the respective module. For example, in an ASC module, it isnecessary to calculate the noise floor of the signal. The calculation ofthe noise floor can be considered to be the analysis function for theASC module. The output of the analysis function for the example ASCmodule, the noise floor, can be used within the ASC module, and/or inputinto one or more other modules of the signal path. The other modules 504a-504 c, which can also contain one or more analysis functions, candetermine a new item of information required for the specific purpose ofthat individual module, and/or can use information passed to it fromother modules 504 a-504 c of the signal path in its calculations. Insome embodiments, one or more of modules 504 a-504 c does not have itsown analysis function 506 a-506 c but relies on information gathered byother modules of the signal path to perform its function.

One potential issue that may arise with allowing each module 504 a-504 cto switch itself on or off or to enable or disable other modules 504a-504 c is how to coordinate these communications such that the variousselection functions 516 a-516 c of the modules 504 a-504 c do notcounteract each other. One method is for each module 504 a-504 c tobroadcast its status to all other modules with the signal 512 a-512 b. Agiven module then examines the status of the rest of the modules 504a-504 c in the signal path and determines, based on a set of rulesdependent on the state of the system, the appropriate action to take.For example, a system-wide prioritized hierarchy of actions might bedefined, such as wind noise reduction being a higher priority thanspectral enhancement. Should wind noise be detected in this example, anymodule implementing a spectral enhancement algorithm at another point inthe signal path can monitor this information, and wait for the windnoise to be reduced, before enabling their function.

FIG. 6 is an example block diagram of an example hearing prosthesis 600with multiple signal paths. The functional aspects of FIGS. 3, 4, and 5may be applied to the configuration shown in FIG. 6 . Additionally,method 700 of FIG. 7 may also be performed on a device with multiplesignal paths like the one shown in FIG. 6 . Further, the configurationshown in FIG. 6 is one example of a hearing prosthesis with multiplesignal paths; blocks may be added, subtracted, or moved and stillfunction within the scope of this disclosure. Moreover, each block ofFIG. 6 may function in a similar manner to the Modules disclosed withrespect to FIGS. 4 and 5 .

The example hearing prosthesis 600 includes two omnidirectionalmicrophone inputs 602 a and 602 b. The microphone inputs 602 a and 602 bwill capture sound for processing by the hearing prosthesis. The outputof the microphone inputs 602 a and 602 b will be passed to block 606where the signals from microphone inputs 602 a and 602 b are analyzed todetermine a front directional signal and a rear directional signal. Insome additional embodiments, block 606 may determine a desired signaland a noise signal. Once block 606 determines some characteristics ofthe signals from microphone inputs 602 a and 602 b, the two signals fromblock 606 are passed to a beamformer 608. The beamformer may postprocess the signals from block 606 to determine a single signal forfurther processing in the hearing prosthesis. In some embodimentsbeamformer 608 may apply a weighting factor to each signal to create avirtual beam to produce a desired signal. In other embodiments,beamformer 608 may attempt to remove the noise signal from the desiredsignal.

Additionally, the example hearing prosthesis 600 includes a telecoil 604a, an external auxiliary (AUX) input 604 b, and a wireless audio input604 c as further inputs. The three inputs 604 a-604 c all provide asignal to an accessory input signal conditioning and management block610. Accessory input signal conditioning and management block 610monitors the signals provided from the various inputs to determine which(or if) any of the inputs are providing a desirable signal. For example,if none of the three inputs 604 a-604 c are providing any signals, thenaccessory input signal conditioning and management block 610 will notprovide a signal to the rest of the signal pathway. However, sometimesmore than one of the three inputs 604 a-604 c may be providing a signalthen accessory input signal conditioning and management block 610 mustdetermine which signal to pass to the rest of the signal pathway. Insome embodiments, there may be an external control switch to select aninput for accessory input signal conditioning and management block 610.In other embodiments, accessory input signal conditioning and managementblock 610 may select a signal based on the quality of the receivedsignals. Further, a processor in the hearing prosthesis may select asignal based on other criteria. Additionally, accessory input signalconditioning and management block 610 may also convert signals to anappropriate signal to pass to the rest of the signal pathway.

The mixing control 612 is configured to receive signals from both thebeamformer 608 and the accessory input signal conditioning andmanagement block 610. In some embodiments, mixing control 612 willselect either the signal from the beamformer 608 or the signal fromaccessory input signal conditioning and management block 610. However,in other embodiments, the mixing control will combine the two signalswith some ratio to pass down the signal path. Mixing control 612 mayeither have an external control (i.e. a user may be able to switch thepath) or it may have a dynamic software control. When mixing control 612has a dynamic software control, a processor in the hearing prosthesismay select how signals are passed. For example, the processor may havemixing control 612 only pass the signal from the telecoil until eitherof the two omnidirectional microphone inputs 602 a and 602 b receive aloud sound.

The output from the mixing control 612, is fed to sound processor 614.Sound processor 614 may be similar to the other various sound processorsdisclosed herein. The sound processor 614 may perform various signalprocessing functions on the audio signal from mixing control 612. Forexample, the sound processor 614 may perform signal processing specificto a prosthesis recipient. The signal processing may be related to ahearing impairment of the prosthesis recipient. Additionally, the soundprocessor 614 may perform other signal processing functions, such asnoise reduction and/or altering amplitudes of frequency components ofthe audio signal. Further, the sound processor 614 may output a signalvia one of two outputs, cochlear implant (CI) processing 616 a orhearing aid (HA) processing 616 b. Sound processor 614 may either havean external control (i.e. a user may be able to switch the output) or itmay have a dynamic software control. When sound processor 614 has adynamic software control, the processor itself may select how signalsare output.

The blocks for both cochlear implant (CI) processing 616 a or hearingaid (HA) processing 616 b provide further sound processing specific tothe type of hearing prosthesis. In some embodiments, the sound processormay be able to function in a CI or HA system, thus both signalprocessing pathways may be present. Both CI processing 616 a and HAprocessing 616 b ultimately produce a signal that will provide astimulation to a prosthesis recipient.

The example hearing prosthesis 600 may include environmentalclassification, as disclosed with respect to FIGS. 3, 4, and 5 , at eachpoint in the signal pathway that has an arrow in FIG. 6 . Based on adetermined classification, information about the audio signal can berelayed to various modules throughout hearing prosthesis 600 based onthe classification determined at different points in the signal pathway.

In one example embodiment, the hearing prosthesis may providesimultaneous environmental classifications of the front and rear facingmicrophone signals, created at the output of module 606. If the frontfacing microphone signal is classified as speech, while the rear facingmicrophone is classed as being noise, this information can be providedto the beamformer to instruct it to reduce noise from the rear directiononly. Alternatively, if the front facing microphone signal is classifiedas noise, while the rear facing microphone is classed as being speech,this information can be provided to the beamformer to instruct it toreduce noise from the front direction only. Other implementations arepossible as well.

In another example embodiment, the hearing prosthesis may providesimultaneous environmental classifications of all accessory inputs, andprovide this information to module 610, where priorities might beassigned to those inputs with speech, over inputs providing noise and/ormusic.

In another example embodiment, the hearing prosthesis may receive adesired audio input signal through the telecoil input 604 a. Thisdesired input may be used to ultimately provide a stimulation to theprosthesis recipient. However, during operation in telecoil mode, theprosthesis may receive an audio signal via omnidirectional microphone 1602 a that indicates a fire alarm. An environmental classifier mayrecognize the high sound level and classification of the fire alarm andresponsively transmit a signal to mixer control 612. The mixer control612 may responsively modify the mixing level.

By modifying the mixing level, a prosthesis recipient, who is operatingthe prosthesis in a telecoil mode would be able to hear the fire alarmas well. This is because in a typical telecoil mode, the microphone maybe completely muted. Once the mixing is adjusted, a portion of themicrophone signal may be combined with the telecoil signal. Thiscombined signal would then ultimately be applied to the prosthesisrecipient. Further, once the mixer has been adjusted, an environmentalclassifier located after the mixing control 612 may classify the signalas having noise which is too loud on a specific frequency band. Theclassifier may provide this information to sound processor 614 which mayresponsively adjust a gain table. This example is just one example ofhow the disclosed methods and apparatuses may be used in a hearingprosthesis with multiple signal pathways. Any combination ofclassification and modifications to system parameters may be used withthe hearing prosthesis 600.

FIG. 7 is one example method 700 for a sound processor. As part ofmethod 700, the sound processor 104 receives an audio signal at block702 and transforms it into an output signal at block 712. Method 700 isone example layout for an example method. In different embodiments, someblocks are combined, added, or omitted. Additionally, some blocks may beperformed in parallel or in sequence. Further, method 700 may beperformed by a processor located within the hearing prosthesis.

The method 700 distributes some sensing and control functions throughoutthe signal path. Once a signal is received by the sound processor 104 atblock 702, the signal is analyzed more than once to determine whatsignal processing functions should be enabled. More specifically, atblock 704 the sound processor 104 analyzes the audio signal to determinea first feature of the signal. Further, at block 704 the sound processor104 detects features from the first audio signal (for example amplitudemodulation, spectral spread). Upon detecting features, the soundprocessor 104 responsively uses these features to classify the soundenvironment (for example into speech, noise, music). The sound processor104 makes a classification of the type of signal present based onfeatures of the signal.

At block 706, the sound processor 104 in the hearing prosthesis 101enables a sound processing mode based on the features of the audiosignal determined at block 704. In some embodiments, the processor inthe hearing prosthesis also uses the sound environment to determinewhich signal processing mode to enable. Further, the sound processoralso controls parameters associated with the processing mode. Forexample, if the determined feature is noise, the processor may decidethat the noise-reduction mode should be enabled, and/or the gain of thesystem should be reduced appropriately. Further, upon the processordetermining a sound processing mode, the determined sound processingmode is applied to the first signal creating a transformed signal.

At step 708 the sound processor detects features from the transformedaudio signal. Upon detecting features, the sound processor responsivelyuses these features to classify the sound environment (for example intospeech, noise, music) based on the transformed signal. In someembodiments, features are detected in the transformed signal that werenot detected in the first signal. For example, a voice signal may bedetected in the transformed signal although it was masked by noise whenthe first signal was analyzed.

At step 710, the processor in the hearing prosthesis enables a secondsound processing mode based on the determined features of thetransformed signal. In some embodiments, the processor in the hearingprosthesis also uses a sound environment associated with the featuresdetected in the second signal to determine which signal processing modeto enable for the second signal processing mode. Further, the soundprocessor also controls parameters associated with the second processingmode. For example, if the determined feature is a voice, the processormay decide that the voice enhancement mode should be enabled, and/or thegain of the system should be increased appropriately.

Further, upon the processor determining a sound processing mode, thedetermined sound processing mode is applied to the transformed signal bythe processor creating an output signal. In some embodiments, steps 708and 710 are repeated to further identify features. Many signalprocessing modes are enabled sequentially (or simultaneously) with themethods disclosed herein. In yet another embodiment, signal processingmodes are disabled based on determined features of the various signals.

At step 712, the output signal is output from the sound processor. Insome embodiments, the output signal is transformed into a stimulus toapply to a prosthesis recipient. However, in other embodiments, it isfurther processed by the hearing prosthesis.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. A method, comprising: performing a first type ofclassification analysis to determine a first environmentalclassification of a first signal at a first location in a signalprocessing path of a device; selecting, based on the first environmentalclassification, a first processing mode; converting, in accordance withthe first processing mode, the first signal into a second signal;performing a second type of classification analysis that is differentfrom the first type of classification analysis to determine a secondenvironmental classification, different from the first environmentalclassification, of the second signal at a second location in the signalprocessing path, the second signal being previously converted from thefirst signal in accordance with the first processing mode; selecting,based on the second environmental classification, a second processingmode; converting, in accordance with the second processing mode, thesecond signal into a third signal; and generating stimulating signalsfor delivery to a recipient of the device based on the third signal. 2.The method of claim 1, wherein selecting the first processing modecomprises: selecting a noise reduction mode.
 3. The method of claim 1,wherein selecting the first processing mode comprises: selecting awind-noise reduction mode.
 4. The method of claim 1, wherein selectingthe second processing mode comprises: selecting a voice enhancementmode.
 5. The method of claim 1, wherein selecting the second processingmode comprises: selecting an output compression mode.
 6. The method ofclaim 1, wherein the second environmental classification is determinedafter the first processing mode is enabled.
 7. The method of claim 1,further comprising: receiving one or more sound signals at the device;and generating the first signal from the one or more sound signals. 8.The method of claim 1, wherein the first signal represents one or moreaudio signals, and wherein performing the first type of classificationanalysis to determine the first environmental classification of thefirst signal comprises: extracting, from the first signal, one or morefeatures of the one or more audio signals; and determining the firstenvironmental classification based on the one or more features extractedfrom the first signal.
 9. The method of claim 8, wherein extracting theone or more features of the one or more audio signals comprises:extracting one or more of a signal level, a signal modulation depth, asignal rhythmicity, a signal spectral spread, or signal frequencycomponents of the one or more audio signals.
 10. The method of claim 1,wherein: performing the first type of classification analysis includesperforming a noise classification analysis; selecting the firstprocessing mode includes selecting a noise reduction mode; convertingthe first signal into the second signal includes reducing noise in thefirst signal; and performing the second type of classification analysisincludes performing a voice classification analysis on the second signalthat includes reduced noise.
 11. The method of claim 1, whereinperforming the first type of classification analysis to determine thefirst environmental classification of the first signal comprisesselecting the first environmental classification from a first pluralityof environmental classifications, wherein performing the second type ofclassification analysis to determine the second environmentalclassification of the second signal comprises selecting the secondenvironmental classification from a second plurality of environmentalclassifications, and wherein the first plurality of environmentalclassifications and the second plurality of environmentalclassifications are different from one another.
 12. The method of claim1, wherein the first type of classification analysis comprises anenvironmental analysis, and wherein the second type of classificationanalysis comprises a voice analysis, different from the environmentalanalysis.
 13. One or more non-transitory computer readable storage mediaoperable with a hearing device, wherein the storage media comprisesinstructions that, when executed by at least one processor, are operableto: perform a first type of classification analysis to classify a soundenvironment of an input signal received at the hearing device as a firstsound environment; enable, based on the classification of the soundenvironment of the input signal as the first sound environment, a firstprocessing mode; transform the input signal into a first transformedsignal using the first processing mode; perform a second type ofclassification analysis to classify a sound environment of the firsttransformed signal as a second sound environment, different from thefirst sound environment; enable, based on the classification of thesound environment of the first transformed signal as the second soundenvironment, a second processing mode; transform the first transformedsignal previously transformed from the input signal into a secondtransformed signal using the second processing mode; and provide thesecond transformed signal to the hearing device, wherein the hearingdevice generates stimulating signals based on the second transformedsignal for delivery to a recipient of the hearing device.
 14. The one ormore non-transitory computer readable storage media of claim 13, furthercomprising instructions operable to: receive a plurality of signalsrepresenting audio signals; and generate the input signal from theplurality of signals.
 15. The one or more non-transitory computerreadable storage media of claim 14, wherein the first processing mode isa mixing ratio of the plurality of signals.
 16. The one or morenon-transitory computer readable storage media of claim 13, wherein theinput signal represents one or more audio signals, and wherein theinstructions operable to perform the first type of classificationanalysis to classify the sound environment of the input signal compriseinstructions operable to: extract, from the input signal, one or morefeatures of the one or more audio signals; and determine theclassification of the sound environment of the input signal as the firstsound environment based on the one or more features extracted from theinput signal.
 17. The one or more non-transitory computer readablestorage media of claim 16, wherein the instructions operable to extractthe one or more features from the input signal comprise instructionsoperable to: extract one or more of a signal level, a signal modulationdepth, a signal rhythmicity, a signal spectral spread, or signalfrequency components of the one or more audio signals.
 18. The one ormore non-transitory computer readable storage media of claim 13, whereinthe instructions operable to enable the first processing mode or thesecond processing mode comprise instructions operable to: enable a noisereduction mode.
 19. The one or more non-transitory computer readablestorage media of claim 13, wherein the instructions operable to enablethe first processing mode or the second processing mode compriseinstructions operable to: enable a wind-noise reduction mode.
 20. Theone or more non-transitory computer readable storage media of claim 13,wherein the instructions operable to enable the second processing modeor the second processing mode comprise instructions operable to: enablea voice enhancement mode.